**3. Physiopathology of carpal tunnel syndrome**

CTS is generally conceded as disarrangement caused by a decoupling of the size of the components of the carpal tunnel, and the space delimited by the fibrous and osseous structures. This is what conditions the compression of the median nerve, altering its irrigation. The compression of the components within the carpal tunnel induces venous congestion and epineural edema, consequently inducing fibroblast invasion in the affected tissue causing constriction and fibrosis of the endoneural compartment of the median nerve. The edema and the epineural and endoneural compression interrupt the axoplasmic flow of nutrients and ions and cause the median nerve to become enlarged [6].

time of ischemia and the repeated number of I/R events. Initially, it leads to an acute lesion proper of the phenomenon, then a major extension of the damage secondary to the repetition of I/R events, since in the CTS, it occurs in an intermittent and prolonged way [7, 10–12].

Current Treatment for Carpal Tunnel Syndrome http://dx.doi.org/10.5772/intechopen.72946 43

There are multiple components in the I/R phenomenon [10, 12]; however, the most important components in the pathological development of the carpal tunnel are as follows: (1) increase in the cytosolic cations' concentration (change in the permeability of the membrane), (2) mitochondrial lesion (alteration of the ATP production and oxidative stress), (3) oxidative stress (production of reactive oxygen and nitrogen species coupled by disruption of redox reaction), (4) immunity-mediated lesion and (5) transcriptional reprogramming [11, 12] (**Figure 3**).

The activation of multiple transporters in the cellular membrane during the I/R phenomenon will lead to major changes (related to cellular microenvironment) in the calcium (Ca2+) and

**Figure 3.** I/R components in carpal tunnel syndrome and pathophysiological events in the damage of local tissues.

**4.2. Components of the I/R injury in the carpal tunnel syndrome**

**4.3. Alteration of the cellular membrane permeability**

Furthermore, the most common diagnosis is idiopathic CTS; nevertheless, recent studies that used magnetic resonance imaging (MRI), histological and biomechanical techniques have strongly suggested that abnormalities of the synovial tissue within the carpal tunnel are closely related to the development of idiopathic CTS, which means that subsynovial connective tissue may be predisposed to shear injury from activity done in 60° of wrist flexion [7].
